Absorbent articles, particularly sanitary napkins, having wings or flaps are disclosed in the patent literature and are available in the marketplace. Sanitary napkins having flaps of the various types are disclosed in U.S. Pat. No. 4,687,478, entitled "Shaped Sanitary Napkin With Flaps", which issued to Van Tilburg on Aug. 18, 1987, U.S. Pat. No. 4,608,047, entitled "Sanitary Napkin Attachment Means", which issued to Mattingly on Aug. 26, 1986, U.S. Patent No. B1 4,589,876, entitled "Sanitary Napkin", which issued to Van Tilburg on May 20, 1986, U.S. Pat. No. 4,285,343, entitled "Sanitary Napkin", which issued to McNair on Aug. 25, 1981, U.S. Pat. No. 3,397,697. entitled "Disposable Sanitary Shield For Undergarments", which issued to Rickard on Aug. 20, 1968, U.S. Pat. No. 2,787,271, entitled "Sanitary Napkin", which issued to Clark on Apr. 2, 1957; and design patent Des. 365,147 issued to Hamel on Dec. 12, 1995.
A number of variations on the types of flaps described above have been presented in an attempt to solve various problems. U.S. Pat. No. 4,900,320 issued to McCoy on Feb. 13, 1990, discloses a sanitary napkin having flaps affixed at points inward from the longitudinal edge of the napkin. U.S. Pat. No. 4,911,701 issued to Mavinkurve on Mar. 27, 1990, discloses a sanitary napkin having elastic means for providing greater convex shape to the body-facing portion of the central absorbent and for enabling adhesive-free placement of the flaps of the napkin. U.S. Pat. No. 4,940,462 issued to Salerno on July 10, 1990, discloses a sanitary napkin with longitudinally expandable flaps. A sanitary napkin having flaps with stress relief means in the form of a notch or a slit is described in U.S. Pat. No. 4,917,697 which issued to Osborn, III, et al. on Apr. 17, 1990. U.S. Pat. No. 5,389,094 issued to Lavash et al. on Feb. 14, 1995, discloses sanitary napkins (and other types of absorbent articles) having flaps and zones of differential extensibility.
Although the sanitary napkins described in the Lavash, et al. patent work quite well, the search for sanitary napkins that have improved flaps has continued. For example, when flaps are wrapped around the curved side edges of the crotch of a wearer's undergarment, stresses are exerted on the flap fasteners, particularly with longer flaps. These stresses tend to cause the flap fasteners to become unattached from the surface to which they are attached, whether it be the underside of the wearer's panties or the opposing flap. This is referred to herein as "wing pop-off". In addition, there is a tendency for the portions of the flaps located in the region of the juncture of the flaps with the main body portion of the sanitary napkin, particularly at those portions of the flaps that are spaced farthest away from the transverse centerline of the flaps (that is, the end portions of the flaps), to wrinkle and be compressed inward due to the forces exerted thereon by the wearer's panty elastics and the wearer's legs.
It is, therefore, an object of the present invention to provide an absorbent article having flaps, such as a sanitary napkin, with a structure that allows the flaps to cover as large an area of the wearer's panties as possible without the fasteners thereon becoming unattached.
It is another object of the present invention to provide an absorbent article having flaps, such as a sanitary napkin, with a structure that resists the tendency for the end portions of the flaps to wrinkle and be compressed inward.
These and other objects of the present invention will be more readily apparent when considered in reference to the following description and when taken in conjunction with the accompanying drawings.